Chaucer and the House of Fame
by Philippa Morgan
Carroll & Graf, 341 pp., $25

Time's Fool
A Mystery of Shakespeare
by Leonard Tourney
Forge, 320 pp., $24.95

The Mask of the Red Death
by Harold Schechter
Ballantine, 308 pp., $24.95

Death by Dickens
edited by Anne Perry
Berkley, 320 pp., $6.99

Ambrose Bierce and the Trey of Pearls
by Oakley Hall
Viking, 216 pp., $24.95

The Tale of Hill Top Farm
by Susan Wittig Albert
Berkley, 286 pp., $22.95

The London Blitz Murders
by Max Allan Collins
Berkley, 260 pp., $6.99

THE LINE BETWEEN FACT AND fancy has always been blurred in tabloid newspapers, plays and movies "based on a true story," biographies for schoolchildren, television commercials, political-campaign material, and other sources of popular entertainment. But in recent years the confusion has spread even to reputably published novels for adults. Consider, for example, the growing fictional practice of making detectives of historical celebrities.

In a small way, the phenomenon has been around for sixty years (or even longer, if you count the nineteenth-century fictionalized exploits of such real-life investigators as Vidocq and Allan Pinkerton). The first author to write a detective series about a historical personage was probably Lillian de la Torre, who cast Dr. Samuel Johnson in the Sherlock Holmes role, with James Boswell as his Watson, for a 1943 short story in Ellery Queen's Mystery Magazine. First collected in book form in Dr. Sam: Johnson, Detector (1946), the series would eventually fill four volumes.

Frederic Dannay, the editorial half of the Ellery Queen team, liked the idea. After publishing mysteries featuring Charlemagne, King Arthur, and Socrates, he discovered and nurtured the versatile Theodore Mathieson, who, beginning in 1959, made one-shot detectives of Leonardo da Vinci, Alexander the Great, Omar Khayyam, Hernando Cortez, Don Miguel de Cervantes, Daniel Defoe, Captain Cook, Dan'l Boone, Stanley and Livingstone, and Florence Nightingale. Mathieson followed his collected stories, The Great "Detectives" (1960), with one of the first novel-length examples, The Devil and Ben Franklin (1961).

Still, as recently as the 1970s, the practice was rare, involving only stray volumes like John Dickson Carr's final novel The Hungry Goblin (1972), with Wilkie Collins as detective, and Margaret Doody's Aristotle Detective (1978).

Then came the deluge. The ranks have included some whose real-life roles made them plausible sleuths--British magistrate Sir John Fielding, Al Capone's nemesis Eliot Ness, onetime New York police commissioner Theodore Roosevelt--while others were more unlikely: Queen Elizabeth I; Edward VII while he was prince of Wales; First Lady Eleanor Roosevelt; and such entertainers as Groucho Marx, the team of Enrico Caruso and Geraldine Farrar (she being the brighter one), and Elvis Presley.

Most of the subjects have been writers, usually but not always those associated with fictional crime. The appearances in detective fiction of Arthur Conan Doyle, who actually had some experience investigating real-life mysteries, have varied from the young medical student playing Watson to his mentor Dr. Joseph Bell (the inspiration for Sherlock Holmes) to the latter-day apologist for spiritualism, often in tandem with Houdini, the debunker of spiritualist frauds rather than the believer. Dashiell Hammett, once a Pinkerton operative, was a natural as a fictional sleuth. Also detecting have been writers outside or on the periphery of the field, including Mark Twain, Jack London, and Jane Austen.